With the increasing mobile phone products with a waterproof function in the sales market, the competitiveness requirement for waterproof reliability and waterproof level is also increased continuously, and the volume of this kind of products will be made smaller and smaller in order to possess better selling points, meanwhile a functional chip gradually occupies more space within the mobile phone body due to performance promotion, and for each key moving part such as a side key, the waterproof design thereof is required to be improved continuously so as to meet the gradually increased requirement for miniaturization.
The side key scheme of the waterproof mobile phones currently sold in the market may be roughly divided into the following forms: 1) FIGS. 1A-1C are schematic diagrams of a structure of a waterproof apparatus for a side key in the related art, as shown in FIGS. 1A-1C, a waterproof plug (101) is made by molding rubber (109), a steel disc (107) and polycarbonate (PC) (108) into one body and it is assembled on a shell (105) to play a waterproof function, and a plastic part of the waterproof plug (101) is pressed with the side key (104) to conduct a pressing action to a switch (102) on a mainboard (103); 2) With the double-shot molding technology, the side-key part is injected onto the shell in a form of rubber (TPU), and the deformability of the rubber and PC itself is used to provide a deformation space for the side-key pressing; and 3) Waterproofing of the key body is realized with the independent key scheme.
The mobile phones using the above structural forms all have certain defects respectively: for the structural mode of the scheme 1, the related process is complicated and the molding cost is relatively high, in general, this scheme is only adopted in high-end mobile phones at present, which is not prospective to have application in various grades of waterproof mobile phones. For the structural mode of the scheme 2, since it is required to inject and mold the side key in a form of rubber with the PC of the shell together by using the double-shot molding technology, there is a great limitation on side-key material selection and appearance processing, and the rigidity of the rubber part of the side key has a great impact on the side-key hand feeling, and when the rubber is used as the side key, if it encounters a maintenance resulted from the puncture of sharp objects, the entire structural component needs to be completely replaced, which has very high maintenance costs. For the structural mode of the scheme 3, though it has flexible replace ability and good appearance processing capacity, the required design space is too large, which is not convenient for production and assembly and does not follow the tendency of waterproof miniaturization.
Therefore, a problem that balanced consideration cannot be given to costs, waterproof performance and miniaturization for waterproofing of the terminal exists in the existing technology.